Basic template for a 2-arm randomised controlled trial

An RCT is a type of study in which participants are randomly assigned to one of two or more clinical interventions. The RCT is generally considered to be the most scientifically rigorous method of hypothesis testing available, and is regarded as the gold standard trial for evaluating the effectiveness of interventions.

A sample of the population of interest is randomly allocated to one or another intervention and the two groups are followed up for a specified period of time. Apart from the interventions being compared, the two groups are treated and observed in an identical manner.

At the end of the study, the groups are analysed in terms of outcomes defined at the outset. The results from, say, the treatment A group are compared with results from the treatment B group. As the groups are treated identically apart from the intervention received, any differences in outcomes are attributed to the trial therapy.

The basic structure of an RCT is shown in the figure above, which is an executable task network for a 2-arm trial modelled in the PROforma language. This network specified the basic workflow in such a trial, without the specific details, patient eligibility criteria, details of the specific treatment protocols in each arm etc. The trial designer can take this general template and add the necessary details to the task definitions to define and run a full trial management procedure.